This is the basis of our component technology; this covers the mozilla/xpcom source directory and includes the "repository". Unlikely a tester would be able to tell there was an XPCOM problem specifically.

It uses (the now deprecated) nsAutoLock.lock/unlock extensively, which means porky.py can't rewrite it automatically. I don't feel comfortable rewriting it by hand.
Assigning to bsmedberg so that he can foist this off on someone else.

Correction: it was nsComponentManager that I didn't want to rewrite. xptinfo was somehow involved in that in a way that I no longer remember.
For the record, porky was able to handle these rewrites, it's just that this code extensively used nsAutoMonitor.lock/unlock, which can't be rewritten automatically (easily).